反应详情

温度

0 °C

To 100 ml. of THF were added 10.6 grams (15 mmoles) of Nα -t-butyloxycarbonyl-L-phenylalanine. The mixture was added dropwise over a one hour period to a mechanically stirred suspension of 0.12 moles of potassium hydride in 250 ml. of dried THF containing 0.5 grams of 18-crown-6-ether at 0° C. and under a nitrogen atmosphere. The mixture was stirred for an additional 10 minutes at 0° C., and a solution of 4 ml. (44 mmoles) of allyl iodide in 20 ml. of THF was added dropwise over a 30 minute period. The resulting mixture was maintained for four hours after which a mixture of 4.6 ml. of glacial acetic acid in 20 ml. of THF was added dropwise. The mixture was stirred for 10 minutes and then was poured onto 400 ml. of ice. The aqueous phase was adjusted to pH 8.0 by addition of 1 N sodium hydroxide. The aqueous phase then was extracted with ether and acidified to pH 2.0 with cold 1 N HCl. The aqueous mixture then was extracted with ethyl acetate. The ethyl acetate was extracted with water, dried over magnesium sulfate, and evaporated in vacuo to a syrup. The syrup was dissolved in 200 ml. of ether, and 8 ml. (0.04 moles) of dicyclohexylamine (DCHA) were added. The resulting precipitate was filtered, and the filtrate was extracted successively with 1.5 N citric acid and water. The ether layer was dried over magnesium sulfate and evaporated in vacuo to obtain 9 grams (74%) of the title compound as a syrup.

1. customat 0° C.
2. temperatureThe resulting mixture was maintained for four hours after which
3. additiona mixture of 4.6 ml
4. stirringThe mixture was stirred for 10 minutes
5. additionwas poured onto 400 ml
6. extractionThe aqueous phase then was extracted with ether
7. extractionThe aqueous mixture then was extracted with ethyl acetate
8. extractionThe ethyl acetate was extracted with water
9. dry with materialdried over magnesium sulfate
10. customevaporated in vacuo to a syrup
11. dissolutionThe syrup was dissolved in 200 ml
12. filtrationThe resulting precipitate was filtered
13. extractionthe filtrate was extracted successively with 1.5 N citric acid and water
14. dry with materialThe ether layer was dried over magnesium sulfate
15. customevaporated in vacuo